From e4e87a2ece1e0c9901514fea094f31863b64b570 Mon Sep 17 00:00:00 2001
From: Andy Shaw <andy.shaw@qt.io>
Date: Wed, 7 Mar 2018 15:12:13 +0100
Subject: sqlite: Prevent a crash when sqlite does not detect any parameters

When using a virtual table inside a SQLite database it is possible that
it does not report the right number of parameters. Therefore we need
to account for this case to prevent it from crashing when trying to
bind parameters it thinks does not exist.

Task-number: QTBUG-66816
Change-Id: I3ff70bb1fe73091f43c3df53616f75858e451cfd
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
---
 src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp     |  5 ++-
 tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp | 41 +++++++++++++++++++++++
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp b/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
index d1a6582c5a..f715d3cba3 100644
--- a/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
+++ b/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
@@ -467,7 +467,10 @@ bool QSQLiteResult::exec()
 
 #if (SQLITE_VERSION_NUMBER >= 3003011)
     // In the case of the reuse of a named placeholder
-    if (paramCount < values.count()) {
+    // We need to check explicitly that paramCount is greater than 1, as sqlite
+    // can end up in a case where for virtual tables it returns 0 even though it
+    // has parameters
+    if (paramCount > 1 && paramCount < values.count()) {
         const auto countIndexes = [](int counter, const QList<int>& indexList) {
                                       return counter + indexList.length();
                                   };
diff --git a/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp b/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp
index a51865897f..c4a27a3175 100644
--- a/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp
+++ b/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp
@@ -176,6 +176,8 @@ private slots:
     void emptyTableNavigate();
     void timeStampParsing_data() { generic_data(); }
     void timeStampParsing();
+    void sqliteVirtualTable_data() { generic_data("QSQLITE"); }
+    void sqliteVirtualTable();
 
 #ifdef NOT_READY_YET
     void task_229811();
@@ -4623,5 +4625,44 @@ void tst_QSqlQuery::dateTime()
     }
 }
 
+void tst_QSqlQuery::sqliteVirtualTable()
+{
+    // Virtual tables can behave differently when it comes to prepared
+    // queries, so we need to check these explicitly
+    QFETCH(QString, dbName);
+    QSqlDatabase db = QSqlDatabase::database(dbName);
+    CHECK_DATABASE(db);
+    const auto tableName = qTableName("sqliteVirtual", __FILE__, db);
+    QSqlQuery qry(db);
+    QVERIFY_SQL(qry, exec("create virtual table " + tableName + " using fts3(id, name)"));
+
+    // Delibrately malform the query to try and provoke a potential crash situation
+    QVERIFY_SQL(qry, prepare("select * from " + tableName + " where name match '?'"));
+    qry.addBindValue("Andy");
+    QVERIFY(!qry.exec());
+
+    QVERIFY_SQL(qry, prepare("insert into " + tableName + "(id, name) VALUES (?, ?)"));
+    qry.addBindValue(1);
+    qry.addBindValue("Andy");
+    QVERIFY_SQL(qry, exec());
+
+    QVERIFY_SQL(qry, exec("select * from " + tableName));
+    QVERIFY(qry.next());
+    QCOMPARE(qry.value(0).toInt(), 1);
+    QCOMPARE(qry.value(1).toString(), "Andy");
+
+    QVERIFY_SQL(qry, prepare("insert into " + tableName + "(id, name) values (:id, :name)"));
+    qry.bindValue(":id", 2);
+    qry.bindValue(":name", "Peter");
+    QVERIFY_SQL(qry, exec());
+
+    QVERIFY_SQL(qry, prepare("select * from " + tableName + " where name match ?"));
+    qry.addBindValue("Peter");
+    QVERIFY_SQL(qry, exec());
+    QVERIFY(qry.next());
+    QCOMPARE(qry.value(0).toInt(), 2);
+    QCOMPARE(qry.value(1).toString(), "Peter");
+}
+
 QTEST_MAIN( tst_QSqlQuery )
 #include "tst_qsqlquery.moc"
-- 
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